设p和q是C^*-代数中的投影,本文给出反交换子pq+qp可逆和Moore-Penrose可逆的充分必要条件,讨论了交换子pq-qp与反交换子pq+pq之间可逆和Moore-Penrose可逆的关系,并得到pq+qp Moore-Penrose逆的计算公式.
We study the necessary and sufficient conditions for the invertibility and Moore-Penrose invertibility of anti-commutator pq + qp when p and q are projections in a C^*-algebra. The relations between the invertibility and Moore-Penrose invertibility of pq - qp and pq + qp are described.